Knob



FIG. 1 shows a front view of a knob showing my new design, viewed from a slightly elevated angle, the back view being identical;

FIG. 2 shows a side view thereof from a slightly elevated angle, the opposite side view being identical;

FIG. 3 shows a top view thereof; and

FIG. 4 shows a bottom view thereof. 

The ornamental design for a knob, as shown and described. 